title: Microfluidic-based patterning of embryonic stem cells for in vitro development studies.
abstract: In vitro recapitulation of mammalian embryogenesis and examination of the emerging behaviours of embryonic structures require both the means to engineer complexity and accurately assess phenotypes of multicellular aggregates. Current approaches to study multicellular populations in 3D configurations are limited by the inability to create complex (i.e. spatially heterogeneous) environments in a reproducible manner with high fidelity thus impeding the ability to engineer microenvironments and combinations of cells with similar complexity to that found during morphogenic processes such as development, remodelling and wound healing. Here, we develop a multicellular embryoid body (EB) fusion technique as a higher-throughput in vitro tool, compared to a manual assembly, to generate developmentally relevant embryonic patterns. We describe the physical principles of the EB fusion microfluidic device design; we demonstrate that >60 conjoined EBs can be generated overnight and emulate a development process analogous to mouse gastrulation during early embryogenesis. Using temporal delivery of bone morphogenic protein 4 (BMP4) to embryoid bodies, we recapitulate embryonic day 6.5 (E6.5) during mouse embryo development with induced mesoderm differentiation in murine embryonic stem cells leading to expression of Brachyury-T-green fluorescent protein (T-GFP), an indicator of primitive streak development and mesoderm differentiation during gastrulation. The proposed microfluidic approach could be used to manipulate hundreds or more of individual embryonic cell aggregates in a rapid fashion, thereby allowing controlled differentiation patterns in fused multicellular assemblies to generate complex yet spatially controlled microenvironments.
authors.affiliation: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA. hang.lu@gatech.edu.
authors.forename: Shalu
authors.initials: S
authors.lastname: Suri
authors.forename: Ankur
authors.initials: A
authors.lastname: Singh
authors.forename: Anh H
authors.initials: AH
authors.lastname: Nguyen
authors.forename: Andres M
authors.initials: AM
authors.lastname: Bratt-Leal
authors.forename: Todd C
authors.initials: TC
authors.lastname: McDevitt
authors.forename: Hang
authors.initials: H
authors.lastname: Lu
mesh_terms: D000818:Animals; D055415:Bone Morphogenetic Protein 4 / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D002478:Cells, Cultured; D058732:Embryoid Bodies / Q000166:cytology / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism; D005326:Fetal Proteins / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008648:Mesoderm / Q000166:cytology; D051379:Mice; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D020825:T-Box Domain Proteins / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D000098908:Brachyury Protein
chemical_list: D055415:Bone Morphogenetic Protein 4; D005326:Fetal Proteins; D049452:Green Fluorescent Proteins; D011993:Recombinant Fusion Proteins; D020825:T-Box Domain Proteins; D000098908:Brachyury Protein